net/virtio: fix buffer leak on VLAN insert
net/virtio: fix buffer leak on VLAN insert

The function rte_vlan_insert may allocate a new buffer for the
vlan header and return a different mbuf than originally passed.
In this case, the stored mbuf in txm[] array could point to wrong
buffer.

Fixes: dd856dfcb9e7 ("virtio: use any layout on Tx")
Cc: stable@dpdk.org

Signed-off-by: Stephen Hemminger <06fa905d7f2aaced6dc72e9511c71a2a51e8aead@networkplumber.org>
Reviewed-by: Jens Freimann <ca9361fbe2c56b38bfc6f0fa839493a196cfbd8f@redhat.com>
Reviewed-by: Maxime Coquelin <9a2667dee3b90866bbc9c2696cff2b7d5616c95a@redhat.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk